alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Gremlin Stealer CnC Successful Exfil Confirmation"; flow:established,to_client; flowbits:isset,ET.Gremlin.Exfil; http.response_body; bsize:27; content:"File|20|uploaded|20|successfully|21|"; reference:md5,fccebee340a7006a339835a290922397; reference:url,unit42.paloaltonetworks.com/new-malware-gremlin-stealer-for-sale-on-telegram; reference:url,community.emergingthreats.net/t/sig-et-malware-possible-gremlin-infostealer-data-upload/2680/1; classtype:trojan-activity; sid:2061960; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_04_29, deployment Perimeter, malware_family GremlinStealer, confidence High, signature_severity Critical, tag c2, updated_at 2025_04_29, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)